Contact arm for distributor breaker plates



June 3, 1952 .1. FlLKO 2,599,323

CONTACT ARM FOR DISTRIBUTOR BREAKER PLATES Filed April 18, 1951 INVENTOR. n JOHN FILKQ m/zwa wz I ATT'YS Patented June 3, 1952 QQNTAO'II ABM FOR DISTRIBUTOR. BREAKER PLATES J hn E lkol'Gh ca p a nor o & B.- M Go Chicago, 111., acorporation of Illinois Applicatin-April18, 1951, Serial No, 221,676"

41 Claims.

Thisinvention relates in general to improve-v ments inthecontact arms mounted on the distributor breaker plate in an automotive ignition system and. is particularly directedto an improved construction for rig-idly securing the rubbing block-of the-contact arm in place thereon.

The contact arm towhichthis invention relates customarily includes a head member of channel formationhaving-acontact button at one end thereof. A spring arm is provided to maintain the contact arm in a normally closed position with respect to a second contact button on the breakerplate. A rubbing block is located intermediate the ends of the head member and has heretofore been secured in place between a part of the head member andone end of the spring arm by means of rivets. normally-formed of a fibrous material and when secured in place merely'by means of rivets, there is a distinct tendency for the assembly to becomeloosened from its holding means. When this-occurs, it becomes necessary to,- replace the entire contact arm.

A further disadvantage which has been encountered in the past with the construction above mentioned is that the fiber rubbing block may become dried out if it remains on the shelffor a long period of time and thereby becomes loosened from the rivets which are supposed to hold it rigidly in place. When this occurs, the entire contact arm must be discarded, thereby resulting ina financial loss to the purchaser.

A further and very important disadvantage in the customary construction of this contact arm arises in the manufacture of the product. When the various elements of the contact arm are being assembled, it is customary to rivet the rub- The rubbing block is bing-blockin place as tightly as possible in order to give it a longer shelf life as well as longer useful l-ifein the ignition system. The nature of the fiber-rubbing block is such that if the rivets are tootight. or if too much pressure is applied at the time of'assembly. the rubbing block will crack thus resulting in'a rejection and a-loss to the manufacturer. By the very nature of-the contact arm'construction, the entire contact'arm must be rejected rather than merely therubbing block.

The-present invention is directed to an improved construction whereby the foregoing disadvantages are entirely overcome thereby increasing-the useful life and theshelflife of the product and avoiding any rejections in the manufacture thereof.

It is; therefore; a principal object of the present invention to provide a novel construction of contact arm adapted for use in connection with the distributor breaker plate of an automotive ignition system which will overcome all the,

disadvantages inherent in constructions used heretofore.

A further object of the invention is toprovide a new. and improved form of mounting means.-

for the rubbing block ofa contact arm which will increase both the shelf life and the useful life of the product.

Another object of the invention is. to provide a contact arm of the character described wherein the rubbing block thereof is. rigidly held in place not only by rivets which have been heretofore used, but also by clamping or clinching the.

rubbing block in. place thereby avoiding the necessity of riveting the rubbing'block so tight during the manufacture thereof as to cause cracking of the block.

A still further object of the invention is. to provide a contact arm of the character described wherein a pair of ears extend outwardly in opposite directions from one edge of the channel shaped head member and which ears are sufficiently long as to enable the ends thereof to be.-

bent around the rubbing block and one end of the spring arm whereby the parts are clamped together and held in that position thereby relieving the rivets from the entire responsibility of holding the rubbing block in place.

Other objects and advantages of the invention will become apparent upon reading the following description taken in conjunction with the accompanying drawing in which:

Fig. 1 is a perspective view-of a typical breaker plate with the contact arm embodying the present invention applied thereto;

Fig. 2 is a perspective view of the improved contact arm illustrating the construction at one side thereof;

Fig. 3 is a perspective view of the improved contact arm showing the opposite side thereof; and

Fig. 4 is a vertical transverse sectional view taken along the plane ofline 4-4 of Fig. 2.

Referring now more particularly to the drawing, it will be understood that there are various types of breaker plates in use depending upon the particular make and year of automobile inwhich it is used. Fig. 1 illustrates a typical breaker plate although it will be understood that the present invention embodied in the-contact arms may be used with other types and forms of breaker plates and ignition systems.

In Fig. 1 the breaker plate itself is illustrated by the numeral I and is shown as having applied thereto a condenser 2, the terminal leads 3 and l and a contact bar 5. The contact arm is indicated generally by the numeral 6 and is mounted for pivotal movement on the bar 5. One end of the bar 5 is provided with an upstanding fiange I having a contact button 8 thereon. A contact button 9 is provided at one end of the contact arm 6 and is normally in contact with the button 8. The buttons 8 and 9 make and break contact in the usual and wellknown manner during the operation of the ignition system.

The opposite end of the contact bar 5 is provided with an upright pivot pin II) adapted to be received by the fiber bushing II of the contact arm 6, thus the contact arm may be rotated about the pivot pin I during the make and break operation of the contact buttons 8 and 9.

Intermediate the ends of the contact bar there is provided an upright flange I2 on which there is mounted a fiber insulating member I3. A lead wire I4 from the condenser 2 has one end thereof mounted on the member I3 and in contact with one end of the terminal lead 4 and the outer free end of the spring arm I5 of the contact arm 6. The normal operation is for the rubbing block I6 to be contacted periodically to break the contact between the buttons 8 and 9. The spring arm I5 returns the arm back to the normally closed position.

The contact arm 6 itself is composed of a head member I I folded longitudinally thereof against itself in channel formation so as to provide the sides I8 and I9. The contact button 9 is mounted on the outer end of the head IT. The other end of the head is provided With the fiber bushing I I adapted to receive the pivot pin II] in order that the arm may be pivoted between open and closed positions.

Intermediate the ends of the head If the sides I B and I9 thereof have formed integral therewith ears 20 and 2|. It will be noted that these cars extend outwardly in opposite directions to provide a bearing surface for a part of the rubbing block I6.

The spring arm I5 terminates at one end thereof in a flat portion as clearly shown at 22 in Fig. 4. This fiat portion 22 is adapted to bear against a part of the rubbing block I6 and on the opposite side thereof from the cars 20 and 2I. The spring arm I5 then extends outwardly for a short distance and is curved so as to partially embrace the bushing I I and then terminates in a free end portion 23 which is secured to the member I3 in contact with the leads 4 and It.

Rivets 24 and 25 pass through the respective ears 2!] and 2|, the rubbing block and the flat portion 22 at one end of the spring arm I5. Heretofore, the ears 20 and 2| merely extended to the edge at each side of the rubbing block I6. The rivets were the sole securing means for fastening the rubbing block in place between the ears 20 and 2I and the flat end 22 of the spring arm I5. As heretofore stated numerous rejections occurred during the manufacture of that construction because the rivets were inserted too tightly causing the rubbing block to crack. The manufacturers felt that it was necessary to thus tightly rivet the block in place in order to prevent the block from becoming loose due to constant use or from becoming loose merely sitting on the shelf. No matter how tightly these parts were riveted together, however, the nature of the rubbing block is such that the rivets alone were insufficient to prevent the block from loosening.

In carrying out the present invention, the ears 20 and 2| are formed so that they extend beyond the sides of the rubbing blocks IS a distance sufficient to enable the ends thereof to be bent inwardly and clampingly embrace the rubbing block and the fiat end 22 of the spring arm I5. Since all of the parts comprising the contact arm are relatively small and require precision in the manufacture thereof, it is necessary that the ends of the ears 20 and 2I overlie the flat end 22 of the spring arm I5 a sufficient distance to afford an effective clamp. Therefore, the outer edge of each ear 20 and 2I is provided with a cut out portion 26 to avoid contact with the slightly extending end "of the adjacent rivet. In the construction shown in Figs. 3 and 4, it will be evident that the ears 20 and 2I are formed of sufficient length to provide wide portions 21 of a length equal to the combined thickness of the rubbing block and the adjacent end 22 of the spring arm. The ears then terminate in the portions 28 which overlie the flat end portion 22 of the spring arm and are folded in that position under sumcient pressure so that the rubbing block is effectively clamped in place.

It has been demonstrated in actual practice that with the present construction, the useful life of the contact arm is tremendously increased because any shrinkage of the rubbing block which may tend to decrease the holding efficiency of the rivets will be overcome by the clamping function of the ears 20 and 2I. These ears have been found to effectively maintain the rubbing block rigid even though the rivets may become loose.

When it was discovered that the clamping action of the ears 20 and 2| were sufficient to maintain the rubbing block rigid even though the rivets became loose, it was no longer necessary to rivet the parts in place as tightly as heretofore, thereby avoiding the possibility of cracking the rubbing block during the manufacture of the contact arm. The rejections of contact arms due to cracked rubbing blocks has been entirely eliminated, thereby decreasing the cost of manufacture.

Changes may be made in the form, construction and arrangement of parts from those dirclosed herein without in any way departing from the spirit of the invention or sacrificing any of the attendant advantages thereof, provided, however, that such changes fall within the scope of the claims appended hereto.

The invention is hereby claimed as follows:

1. A contact arm for use on the distributor breaker plate of an automotive ignition system comprising a head member adapted to pivot about one end thereof and having a pair of ears intermediate the ends thereof extending outwardly in opposite directions, a spring arm terminating at one end thereof adjacent said ears in a substantially fiat portion spaced from the ears, a rubbing block positioned in the space between the end of said spring arm and said ears, and means for rigidly securing said rubbing block in place including rivets passing through said ears, block and spring arm, and the ends of said ears being bent clampingly around the sides of said block and said flat portion of the spring arm.

2. A contact arm for use on the distributor breaker plate of an automotive ignition system comprising a head member adapted to pivot about one end thereof and having a pair of ears intermediate the ends thereof extending outwardly in opposite directions, a spring arm terminating at one end thereof adjacent said ears in a substantially flat portion spaced from the cars, a rubbing block positioned in the space between the end of said spring arm and said ears, and means for rigidly securing said rubbing block in place including rivets passing through said ears, block and spring arm, and clamping means embracing said block and the flat portion of said spring.

3. A contact arm for use on the distributor breaker plate of an automotive ignition system comprising a head member adapted to pivot about one end thereof and having a, pair of ears intermediate the ends thereof extending outwardly in opposite directions, a spring arm terminating at one end thereof adjacent said ears in a substantially flat portion spaced from the ears, a rubbing block positioned in the space between the end of said spring arm and said ears, and means for rigidly securing said rubbing block in place including rivets passing through said ears, block and spring arm, and clamping means embracing said block and the flat portion of said spring at each side thereof.

4. A contact arm for use on the distributor breaker plate of an automotive ignition system comprising a head member adapted to pivot about one end thereof and having a pair of ears intermediate the ends thereof extending outwardly in opposite directions, a spring arm terminating at one end thereof adjacent said ears in a substantially fiat portion spaced from the cars, a rubbing block positioned in the space between the end of said spring arm and said ears, and means for rigidly securing said rubbing block in place including rivets passing through said ears, block and spring arm, and clamping means integral with said head member embracing said block and the fiat portion of said spring at each side thereof.

JOHNl FILKO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,851,568 Davis Mar. 29, 1932 2,025,191 Davis Dec. 24, 1935 

